drastic loss of power with bad missing

[dingah2]

Just discovered a bad spark plug during dyno tune went to get replacement - hold on Ford now have a new NGK plug specific to the T have to wait 24 hours to get them in.....still waiting for result and will advise.

DIngah

[moorus]

Car goes in monday for a new turbo. It is getting the overboost fault code and this is fords latest try to fix. Also scooter mine is a Aug 03 make.

[Phils XM]

Have had the same missing problem a few times now, Had it check at John McGrath ford in Philip and they found an overboost code (in late feb, warm day) told me I should rewiew my driving style????(useless w@nkers)

Has happened a few times since, some when cold starting and some on the open road.

[loop]

Had my car looked at on friday for overboost and wastegate errors. The mechanic told me he was advised by Foerd tech support to disconect one of the sensors.

I couldn't get much more info out of him than that but he told me if it seems to be going too much better I should bring it back strait away.

He said this was fords temperary fix for the problem.

[dingah2]

Phils Xm - couldn't agree more about McGrath. Yes they may have the number one Ford sales teeam based on numbers but when it comes to maintenance they are absolutely average on a good day. They have no one person there who comes even close to being a maintenance guru - and you'd think every warranty claim comes out of their own pockets. I think I'll take my servicing elsewhere and give Gregory's a try.

Dingah

[dingah2]

Forgot to add for non-warranty work I use Dyanmic Tuning and Service (used to be Ming Automotive) Lyell Street Fyshwick - top notch service and knowledge of the T game - Glen's the tuning genius - worth checking out with your problem.

Dingah

[tupperware]

What they are saying it is is that the vehicles are going into an "overboost" situation where the PCM(Powertrain Control Module) detects a "missfire" in the engine and overcompesates for the sudden drop in engine performance by momentarily increasing the boost pressure(as high as 9psi).Then it detects that the missfire has gone and the system logs an overboost code and goes into limited operation or forced throttle shutdown.

Fordtech,

I don't think I fully understand the purpose of this "missfire" compensation.

If the PCM detects a missfire why would it attempt to create more cylinder pressure by raising the boost? Wouldn't this only encourage further missfires?

Even if it didn't missfire again, wouldn't the power spike (missfire compensation) immediately after the missfire give the sensation of a larger missfire?

Sorry, I don't mean to be argumentative, but it just seems like a PCM function that has no worth.

Confused Cameron

[Guest vosadrian]

I believe ford have gone over the top with protections in this ECU. I don't quite understand this attitude. The more fast Ts around, the more they are likely to sell more of them. The car was made to be modified. I understand warranty concerns etc. But they should have put more effort into monitoring things so they could refuse warranty when they detect that mods have been done, and less effort into making the thing protect itself to the detriment of people wanting to modify them.

-- Adrian

[Guest sancho]

Vosadrian: yes that is indeed correct, but theres just one problem. Ford are just dumb wankers. Their engineers are smart and do thier job well, but the guru's at Ford who make all the dicisions about which why they go with what they have...dont know sh*t from clay.

[colbourne]

I have had a similar problem with a BA XR8 and I reckon it probably was caused by low fuel in the tank being sloshed around by the acceleration and twisty road causing low fuel pressure. This would be quite serious for a modified XR6T as you would be running lean with damage inevitable thus Ford have probably built in extra safe guards.

Have any other XR8 owners had this problem of misfiring at full throttle ( not on rev limiter).